Extended Theories of Gravity with Generalized Energy Conditions

Spanish Relativity Meeting: almost 100 years after Einstein's revolution

Mimoso, J.P.^1,2 ; Lobo, F.S.N.^1,2 ; Capozziello, S.^3,4

Departamento de Física, Faculdade de Ciências, Edifício C8, Lisbon, Campo Grande

P-1749-016, Portugal^1

Instituto de Astrofísica e Ciências Do Espaço, Faculdade de Ciências, Edifício C8, Lisbon, Campo Grande

P-1749-016, Portugal^2

Dipartimento di Fisica, Università di Napoli Federico II, Napoli, Italy^3

INFN Sez. di Napoli, Compl. Univ. di Monte S. Angelo, Edificio G, Via Cinthia, Napoli

I-80126, Italy^4

关键词: Einstein field equations;    Energy condition;    Energy-momentum tensor;    Field equation;    Gravity theory;    Scalar fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/600/1/012047/pdf
DOI  :  10.1088/1742-6596/600/1/012047

来源: IOP

【 摘 要 】

We address the problem of the energy conditions in modified gravity taking into account the additional degrees of freedom related to scalar fields and curvature invariants. The latter are usually interpreted as generalized geometrical fluids that differ in meaning with respect to the matter fluids generally considered as sources of the field equations. In extended gravity theories the curvature terms are encapsulated in a tensor Haband a coupling g(Ψi) that can be recast as effective Einstein field equations, with corrections to the energy-momentum tensor of matter. The formal validity of standard energy inequalities does not assure basic requirements such as the attractive nature of gravity, so we argue that the energy conditions have to be considered in a wider sense.